Poly(arylene benzimidazole)s as novel high-performance polymers

Series of novel poly(arylene benzimidazole)s (PABIs) was obtained by condensation polymerization of aromatic bifluorides with the monomers of di(benzimidazolyl) benzenes (synthesized by reaction of the isomeric phthalic acids with o-phenylenediamine) via a C-N coupling reaction. The structures of this series of polymers were characterized by Fourier transform infrared, proton nuclear magnetic resonance (H-1 NMR) spectroscopy and elemental analysis, and the results showed good agreement with the proposed structures. These synthesized polymers exhibited relatively high glass- transition temperatures (T-g > 240 degrees C), good thermal stability with high decomposition temperatures (T-d > 450 degrees C) and excellent solubility in organic solvents. On the atomic scale, the molecular simulation results indicated that the PABI polymers exhibited a zigzag molecular chain structure with a high free volume fraction due to the different linkage modes of the monomers in the polymerization process. On the macro level, the PABI polymers possessed high tensile strength with good toughness; the mechanical behavior of the PABI polymers indicates that they can be considered a new class of high-performance polymers.